not an issue, that's a problem in your own solution (and the error message more or less tells you from where your problem comes)

I have the same issue. I pass all the tests but get this error under the "STDERR". What does it mean?

Time: 850ms Passed: 27 Failed: 0 Exit Code: 1
Test Results:
Sample tests (7 of 7 Assertions)
More tests (10 of 10 Assertions)
Random tests (10 of 10 Assertions)

STDERR
Traceback (most recent call last):
File "main.py", line 60, in
test.assert_equals(solve_runes(s), solveDarkRunes(s))
File "/home/codewarrior/solution.py", line 16, in solve_runes
elif eval(runes_list[0]) == eval(runes_list[1]):
File "", line 1
-0633
^
SyntaxError: invalid token